add support for windows newlines in b3sum --check

Fixes #222.

2 files changed, 32 insertions, 14 deletions

diff --git a/b3sum/src/main.rs b/b3sum/src/main.rs
index a55d910..baa6b6c 100644
--- a/b3sum/src/main.rs
+++ b/b3sum/src/main.rs
@@ -244,8 +244,11 @@ fn filepath_to_string(filepath: &Path) -> FilepathString {
         filepath_string = filepath_string.replace('\\', "/");
     }
     let mut is_escaped = false;
-    if filepath_string.contains('\\') || filepath_string.contains('\n') {
-        filepath_string = filepath_string.replace('\\', "\\\\").replace('\n', "\\n");
+    if filepath_string.contains(['\\', '\n', '\r']) {
+        filepath_string = filepath_string
+            .replace('\\', "\\\\")
+            .replace('\n', "\\n")
+            .replace('\r', "\\r");
         is_escaped = true;
     }
     FilepathString {
@@ -303,6 +306,7 @@ fn unescape(mut path: &str) -> Result<String> {
         match path[i + 1..].chars().next().unwrap() {
             // Anything other than a recognized escape sequence is an error.
             'n' => unescaped.push_str("\n"),
+            'r' => unescaped.push_str("\r"),
             '\\' => unescaped.push_str("\\"),
             _ => bail!("Invalid backslash escape"),
         }
@@ -321,13 +325,11 @@ struct ParsedCheckLine {
 }
 
 fn parse_check_line(mut line: &str) -> Result<ParsedCheckLine> {
-    // Trim off the trailing newline, if any.
-    line = line.trim_end_matches('\n');
+    // Trim off the trailing newlines, if any.
+    line = line.trim_end_matches(['\r', '\n']);
     // If there's a backslash at the front of the line, that means we need to
     // unescape the path below. This matches the behavior of e.g. md5sum.
-    let first = if let Some(c) = line.chars().next() {
-        c
-    } else {
+    let Some(first) = line.chars().next() else {
         bail!("Empty line");
     };
     let mut is_escaped = false;
diff --git a/b3sum/src/unit_tests.rs b/b3sum/src/unit_tests.rs
index 1fa1a17..b95c4a2 100644
--- a/b3sum/src/unit_tests.rs
+++ b/b3sum/src/unit_tests.rs
@@ -28,13 +28,13 @@ fn test_parse_check_line() {
         file_path,
         expected_hash,
     } = crate::parse_check_line(
-        "fafafafafafafafafafafafafafafafafafafafafafafafafafafafafafafafa  fo \to\n\n\n",
+        "fafafafafafafafafafafafafafafafafafafafafafafafafafafafafafafafa   \t\r\n\n\r \t\r\n\n\r",
     )
     .unwrap();
     assert_eq!(expected_hash, blake3::Hash::from([0xfa; 32]));
     assert!(!is_escaped);
-    assert_eq!(file_string, "fo \to");
-    assert_eq!(file_path, Path::new("fo \to"));
+    assert_eq!(file_string, " \t\r\n\n\r \t");
+    assert_eq!(file_path, Path::new(" \t\r\n\n\r \t"));
 
     // path is one space
     let crate::ParsedCheckLine {
@@ -71,20 +71,20 @@ fn test_parse_check_line() {
         assert_eq!(file_path, Path::new("fo\\a\\no"));
     }
 
-    // escaped newline
+    // escaped newlines
     let crate::ParsedCheckLine {
         file_string,
         is_escaped,
         file_path,
         expected_hash,
     } = crate::parse_check_line(
-        "\\4444444444444444444444444444444444444444444444444444444444444444  fo\\n\\no",
+        "\\4444444444444444444444444444444444444444444444444444444444444444  fo\\r\\n\\n\\ro",
     )
     .unwrap();
     assert_eq!(expected_hash, blake3::Hash::from([0x44; 32]));
     assert!(is_escaped);
-    assert_eq!(file_string, "fo\\n\\no");
-    assert_eq!(file_path, Path::new("fo\n\no"));
+    assert_eq!(file_string, "fo\\r\\n\\n\\ro");
+    assert_eq!(file_path, Path::new("fo\r\n\n\ro"));
 
     // Escaped newline and backslash. Again because backslash is not allowed on
     // Windows, this test is Unix-only.
@@ -187,3 +187,19 @@ fn test_parse_check_line() {
         .unwrap_err();
     }
 }
+
+#[test]
+fn test_filepath_to_string() {
+    let output = crate::filepath_to_string(Path::new("foo"));
+    assert_eq!(output.filepath_string, "foo");
+    assert!(!output.is_escaped);
+
+    let output = crate::filepath_to_string(Path::new("f\\ \t\r\noo"));
+    if cfg!(windows) {
+        // We normalize backslashes to forward slashes on Windows.
+        assert_eq!(output.filepath_string, "f/ \t\\r\\noo");
+    } else {
+        assert_eq!(output.filepath_string, "f\\\\ \t\\r\\noo");
+    }
+    assert!(output.is_escaped);
+}